The invention relates to self-lubricating abrasion resistant compositions useful for a wide rage of appli- cations. Particular utility is found in the dental and medical arts where such compositions are suitable for the formation and construction of dental prosthesis such as artificial teeth, inlays, onlays, and facings, crowns and bridges and artificial bone parts and medical prosthetic body pars, such as knee joints and/or other bone engaged surfaces and the like where abrasion resistance, polishability and aesthetics are important.
Artificial teeth should exhibit certain physical and physiochemical characteristics to be suitable for use. They should be hard and resistant to chipping, durable, and stable to solvents, water, and heat. In addition, they should be of an aesthetically acceptable color, i.e., close to that of natural teeth, or be amenable to arti- ficial coloration. The teeth should not cause excessive wear to opposing natural or artificial teeth, should not wear out of conclusion, and should be capable of being bonded firmly to supportive structures. They should also be amenable to ordinary means of physical shaping, grinding, and polishing, so as to minimize production cost.
Various metals and ceramics as used in the formation of prior art artificial teeth and other dental appliances possess certain inherent deficiencies which lessen their desirability in dental applications. Thus, the metallic color of gold, amalgam, and other metallic species sees as an aesthetic detraction to the wearer of appliances made therefrom. In addition, the high cost most noble metals from which many such appliances are commonly made leads to a cost consideration whenever their use is con- templated. Ceramic materials, another common alternative, are often difficult to form into acceptable shapes, and may tend to be abrasive and aesthetically unpleasant surfaces upon the physical wearing of surface layers. Such materials are also difficult to polish satisfactorily. These reasons together with factors related to cost, to consumer preference, to the technical skills of dental practitioners, and to convenience have motivated a search for alternative positions suitable for the construction of dental appliances, inlays, onlays, crown and bridge material, artificial teeth and the like.
Of the presently available organic compositions used for the construction of artificial teeth, most are com- posed of acrylics, often crosslinked by polyfunctional moieties.
As used herein "self-lubricating material" means a material which is adapted to increase the lubricity of a product surface Preferably self-lubricating material for use as particles in prostheses in accordance with the invention has a kinetic coefficient of friction less than 0. 25 when measured using ASTM D 1894-78 with a load of 5 psi.
As used herein ASTM D 1894-78 is carried out using water and the same materials.
As used herein "water insensitive" means that water does not have a material effect upon the material so characterized.
It is to be understood that the term "bisphenol-Al" is commonly utilized in the art to indicate the chemical compound 2,2-bis(4-hydroxyphenyl)propane. It is also to be understood that the term "bis-GMA" is commonly used to indicate the chemical compound 2,2-bis(4-(2-hydroxy-3- methacryloxypropoxy) phenyl) propane, otherwise referred to as "digycidyl methacrylate ester of bisphenol-A."
Dentsply U.S. Pat. Nos. 4,396,476, 4,396,377 and 4,698,373 (the disclosures of which are incorporated herein by reference) disclose interpenetrating network teeth but do not disclose self-lubricating abrasion resistant compositions as required by the applicant's invention.
Thornton U.S. Pat. No. 2,345,305 as discloses making artificial teeth comprised of different plastic materials for the face ("enamel") and body portions. Note FIG. 17, and page 4, column 2, lines 21-24. Another composite plastic tooth structure is disclosed by Cornell U.S. Pat. No. 3,488,846.
The Rosenkranz et al. U.S. Pat. No. 3,928,299 dis- closes an organic homopolymer or random copolymer contain- ing urethane groups.
Michl et al. in U.S. Pat. Nos. 4,267,097 and 4,281,991 (the disclosures of which are incorporated herein by reference) disclose artificial teeth prepared from (a) particle/bead, (b) a liquid monomer such as the adduct of hydroxymethacrylates and diisocyanates or difunctional esters of (meth) acrylic acids or mixtures thereof, and (c) micro-fine inorganic fillers. Michl et al do not disclose self-lubricating abrasion resistant hardenable compositions as required by Applicants' inven- tion.
Walkowiak et al. in U.S. Pat. No. 4,308,190 and 4,369,262 disclose dental paste materials of a polymeriz- able acrylic ester, a crosslinked bead polymer, and a particulate inorganic filler and do not disclose self- lubricating abrasion resistant hardenable compositions, or interpenetrating network compositions for making artificial teeth as required by Applicants' invention.
Simpson in U.S. Pat. No. 4,361,676 discloses a sag resistant, pumpable composition comprising a liquid mater- ial dispersed throughout a synthetic, continuous cross- linked polymer matrix.
Wright et al. in U.S. Pat. No. 4,598,111 disclose the use of various divinyl compounds, including divinyl dimethylsilane (column 6, line 35) as a crosslinkig agent for (meth)-acrylate monomer Systems. Other patents of this general type include, for example, Kohno et al. U.S. Pat. No. 4,761,436; dimethyldivinylsilane as a co-mono- mer; column 3, line 29); Feinberg et al . U.S. Pat. 4,894,315; column 3, lines 37-38); Fryd et al. U.S. Pat. No. 4,956,252; column 5, lines 43-44); and Kafka et al. U.S. Pat. No. 4,970,037; column 9, lines 16-17).
Yamazaki et al. in U.S. Pat. 4,826,893 disclose a dental composition comprising (a) a siloxane polymer, (b) a monomer copolymerizable with the siloxane polymer, (c) a polymerization catalyst, e.g. benzoyl peroxide, and optionally, (d) a filler.
Laundry in U.S. Patent No. 3,084,436 discloses soft dental materials manufactured from mixtures of methacryl- ate monomers. Monofunctional esters together with vinyl- acetate or vinyl stearate are crosslinked with polyfunc- tional esters of acrylic or methacrylic acid. The result- ing product is disclosed as being three dimensionally crosslinked.
Graham et al. in U.S. Pat. No. 3,087,875 disclose preparation of graft copolymers. Alkyl methacrylate and analogous polymers are dissolved in monomers such as alkyl acrylates, alkyl thioacrylates, and N-vinyl lactams. The monomers are subsequently grafted to the preformed poly- mers via photochemical initiation.
Cornell in U.S. Pat. No. 3,427,274 discloses hard- enable materials formed from a mixture of methyl meth- acrylate homopolymer and styrene-butadiene copolymer latex coated with methyl methacrylate polymer which may be incorporated in a methacrylate-crosslinking agent compo- sition to form hardenable compositions.
Chang in U.S. Pat. No. 3,452,437 discloses a dental restorative material formed from the "diglycidyl methacrylate of bisphenol-A" (bis-GMA) to which a quantity of methyl methacrylate may be added.
Bruckmann et al. in U.S. Patent No. 3,468,977 dis- close the formulation of dental compositions from a mix- ture of a polymer and a monomer. The preformed uncross- linked polymer beads are allowed to swell with monomer which may contain a crosslinkiing agent. Acrylic materials may be used for both the monomer and the polymer.
Petner in U.S. pat. No. 3,470,615, teaches the formulation of a material suitable for use in the con- struction of dental appliances. A mixture of an uncross- linked homopolymer and crosslinked copolymer is dissolved in a liquid polyglycol dimethacrylate to form a suspension which may be brushed on a substratum and subsequently hardened by heat to build up layers of polymeric material. A similar teaching may be found in U.S. Pat. No. 3,471,596, also to Petner et al. A thick liquid is provided which is useful in the building up of dental crowns and the like. The difunctional monomer may contain various thickening agents including poly (methyl methacrylate). In some embodiments, the poly(methyl meth- acrylate) may be supplemented with additional polymer which may be partially crosslinked with allyl methacryl- ate.
Lee in U.S Pat. No. 3,539,533 discloses a filling material including a monomer solution filled with inor- ganic particulate filler. The monomer solution may be a mixture of methacrylate monomers containing bisphenol-A dimethacrylate.
Taylor in U.S. Pat. No. 3,597,389 discloses poly- functional methacrylate monomers, including "bis-phenol-A glycidyl dimethacrylate" (bis-GMA), polymerized with an inorganic filler to yield dental compositions.
Waller in U.S. Pat. No. 3,629,187 discloses the use of the isocyanate or diisocyanate adducts of bisphenol-A type compounds These adducts are employed together with various inorganic fillers and liquid monomers to form liquid or paste compositions which are polymerizable either thermally or photochemically.
Dougherty in U.S. Pat. No. 3,647,498 discloses dental compositions which are composed of liquid-solid mixtures. The solid phase is an acrylate or methacrylate polymer in bead form.
Logemann in U.S. Pat. 3,649,608 discloses dental compositions which comprise solid bead polymers or copoly- mers of methacrylate type materials.
Lee in U.S. Pat. No. 3,751,399 discloses compo- sitions for dental use comprising aromatic and alicyclic polyacrylates which are mixed together with other poly- acrylate compounds especially those containing bisphenol-A structures.
Sperling in U.S. Pat. No. 3,833,404 discloses elas- tomers, especially acrylates, urethanes, butadienes, natural rubbers, and polyvinyl alcohol, are formulated which possess interpenetrating polymeric network type structures. These materials are disclosed as being "hard", but are used as vibration and sound damping insu- lators.
Highgate in U.S. Pat. No. 3,961,379 discloses an article manufactured from a crosslinked polymer which is swollen with a monomer containing a crosslinking agent
Temin in U.S. Pat. No. 4,197,234 discloses dental restorative composite compositions and filler therefor.
Engel in U.S. Pat. No. 4,288,221 discloses durable polishable direct filling material.
Jarby in U.S. Pat. No. 3,469,317 discloses material for filling cavities.
Crowell in U.S. Pat. No. 2,315,503 discloses art of molding composite resins.
Crowell in U.S. Pat. No. 2,403,172 discloses art of molding resins of vinyl type.
Van Beuren Joy in U.S. Pat. No. 3,532,502 discloses dentures, compositions, and methods
Michl et al in U.S. Pat. No. 4,281,991 discloses dental prostheses.
Bauman et al in U.S. Pat. No. 4,771,110 discloses polymeric materials having controlled physical properties and processes for obtaining these.
Muramoto et al in U.S. Pat. No 4,829,127 discloses composite resin particles, its preparation and resinous composition for coating use containing the same.
Bauman in U.S. Pat. No. 4,880,879 discloses abrasion resistant composite material and process for making the same.
Podszun et al in U.S. Pat. No. 4,937,144 discloses dental fillers.
Lee in Australian Patent Specification 50, 674 discloses dental adhesive composites.
None of the foregoing patents discloses the novel compositions and prostheses having matrix material bonded or adapted to be bonded to self-lubricating abrasion resistant particles in accordance with the invention.